From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Nicholas Piggin <npiggin@gmail.com>, Paul Mackerras <paulus@samba.org>
Subject: [PATCH 4/6] powerpc/watchdog: Fix final-check recovered case
Date: Wed, 9 Aug 2017 22:41:24 +1000 [thread overview]
Message-ID: <20170809124126.28907-5-npiggin@gmail.com> (raw)
In-Reply-To: <20170809124126.28907-1-npiggin@gmail.com>
When the watchdog decides to panic, it takes the lock and double
checks everything (to avoid races with the CPU being unstuck or
panic()ed by something else).
The exit label was misplaced and would result in all-CPUs backtrace
and watchdog panic even in the case that the condition was found to be
resolved.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/watchdog.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/watchdog.c b/arch/powerpc/kernel/watchdog.c
index 2806383d2339..5a69654075c1 100644
--- a/arch/powerpc/kernel/watchdog.c
+++ b/arch/powerpc/kernel/watchdog.c
@@ -144,7 +144,6 @@ static void watchdog_smp_panic(int cpu, u64 tb)
for_each_cpu(c, &wd_smp_cpus_pending)
set_cpu_stuck(c, tb);
-out:
wd_smp_unlock(&flags);
printk_safe_flush();
@@ -157,6 +156,11 @@ static void watchdog_smp_panic(int cpu, u64 tb)
if (hardlockup_panic)
nmi_panic(NULL, "Hard LOCKUP");
+
+ return;
+
+out:
+ wd_smp_unlock(&flags);
}
static void wd_smp_clear_cpu_pending(int cpu, u64 tb)
--
2.13.3
next prev parent reply other threads:[~2017-08-09 12:42 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-09 12:41 [PATCH 0/6] watchdog and NMI IPI locking improvements Nicholas Piggin
2017-08-09 12:41 ` [PATCH 1/6] powerpc: NMI IPI improve lock primitive Nicholas Piggin
2017-08-10 12:07 ` [1/6] " Michael Ellerman
2017-08-09 12:41 ` [PATCH 2/6] powerpc/watchdog: Improve watchdog " Nicholas Piggin
2017-08-09 12:41 ` [PATCH 3/6] powerpc/watchdog: Moderate touch_nmi_watchdog overhead Nicholas Piggin
2017-08-09 12:41 ` Nicholas Piggin [this message]
2017-08-09 12:41 ` [PATCH 5/6] powerpc/watchdog: Fix marking of stuck CPUs Nicholas Piggin
2017-08-09 12:41 ` [PATCH 6/6] powerpc/watchdog: add locking around init/exit functions Nicholas Piggin
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